1. Field of the Invention
The present invention relates to a monitoring apparatus and a monitoring method for monitoring an interior of a closed space for passengers which has an opening/closing door and, more particularly, to an image monitoring apparatus and an image monitoring method that makes it possible to detect a confined passenger or a passenger in need of care, or an equipment failure in, for example, a car of an unattended elevator, just from an image supplied by a monitoring camera.
2. Description of the Related Art
An elevator according to the prior art that is fully equipped with various dedicated sensors for primarily monitoring an open or closed state of a door is able to monitor a variety of states by combining diverse sensor outputs. Currently, however, there are many elevators not equipped with dedicated sensors in the market.
FIG. 13 is a block diagram illustrating another prior art disclosed in Japanese Unexamined Patent Publication No. 8-26611. The block diagram shows a conventional monitoring technology described under a title xe2x80x9cAPPARATUS FOR DETECTING OBJECT IN ELEVATOR CAR.xe2x80x9d FIG. 14 is a schematic diagram of the prior art of FIG. 13. The technology described in the literature is for accurately detecting the number of passengers in a car without causing differences in heights of detection objects to deteriorate detection accuracy while preventing erroneous detection at the same time.
Referring to FIG. 13, the apparatus for detecting an object in a car is constituted by an image processor 2001, a television camera 2002, and a passenger detector 2005. An output of the apparatus is transmitted to an elevator controller 2003, and used for carrying out elevator control.
A correction coefficient calculating unit 2011 calculates a correction coefficient for an area of an image of a detected passenger or the like based on a height of an image of a detection object at a particular position. A passenger detecting unit 2010 uses the correction coefficient calculated by the correction coefficient calculating unit 2011, corrects the area of the image of the detected passenger or the like, converts the area into a number of passengers, and outputs the number of passengers. Thus, the height of an object is detected, and a correction coefficient based on the detected height is calculated to correct an area of the object. Hence, the number of passengers in a car can be accurately detected.
There is still another prior art. FIG. 15 is a block diagram showing another conventional monitoring technology described in Japanese Unexamined Patent Publication No. 5-6494 titled xe2x80x9cAPPARATUS FOR MEASURING MOVING OBJECT AND TRAFFIC FLOW MEASURING IMAGE PROCESSOR.xe2x80x9d FIG. 16 schematically shows a monitoring camera installed in an elevator car.
The technology shown in FIG. 15 relates to the apparatus for measuring a moving object for detecting status amounts of a moving object and, more particularly, to a traffic flow measuring image processor for detecting status amounts, such as traffic amount, speed, car-to-car distance, density, occupancy, congestion distance, and time required for passing through a section, in an automobile traffic flow.
Referring to FIG. 15, a vehicle is imaged by a TV camera 3001 controlled by a TV camera control circuit 3002, and the image data is stored in a frame memory 3002. A presence area of the vehicle along a moving path of the vehicle is preset, based on the image data, by a presence area defining circuit 3009. A vertical line detecting circuit 3010 extracts data indicating the vehicle from the image data in the presence area, and the data indicating the vehicle is successively stored in a data time series storage circuit 3012 in time series at a predetermined cycle. Based on the data time series image obtained by the data time series storage circuit 3012, a vehicle determining circuit 3017 determines whether the vehicle moving in the preset presence area is present, and, if so, then a vehicle information measuring circuit 3018 measures a state of the determined vehicle.
Furthermore, according to the prior art shown in FIG. 13, even when the aforesaid dedicated sensors are provided, confinement is presumed by a combination of ON and OFF of sensor signals. Therefore, the prior art shown in FIG. 13 has been presenting a problem in that presence of a passenger in a car does not always coincide with presence of a passenger indicated by a sensor signal because, if a passenger presses a button of a destination floor provided in a car, then it automatically means that there is a passenger in the car.
The problem occurs especially when a child is in a car alone or if a passenger maliciously confines himself in the car.
Although the prior art of FIG. 15 is not intended for detecting a passenger confined in an elevator, if the art shown in FIG. 15 is used to create a confinement detecting apparatus, then a monitoring camera device as shown in FIG. 16 will be installed. The prior art shown in FIG. 15 has also been posing a problem in that a confined passenger cannot be detected just from an image, requiring a dedicated sensor be separately provided, as in the case of an elevator not equipped with a dedicated sensor.
More specifically, in the prior art of FIG. 15, separately existing objects at a substantially constant speed in a view can be recognized. It has been difficult, however, to recognize moving objects in a picture supplied by a monitoring camera showing a mixture of a moving door and moving passengers as in the case of, for example, a picture provided by a camera installed in an elevator car.
Therefore, the prior art of FIG. 15 has been posing a problem in that it is difficult to detect confined passengers from a picture where different movements exist if the prior art is applied as it is for detecting confined passengers, although the prior art of FIG. 15 is not intended for detecting confined passengers.
Accordingly, the present invention has been made with a view toward solving the problems described above, and it is an object thereof to provide an image monitoring apparatus and an image monitoring method that allow a confined passenger to be detected just from an image without using a dedicated sensor.
To this end, according to one aspect of the present invention, there is provided an image monitoring apparatus for monitoring an interior of a closed space having an opening/closing door, including: image acquiring means provided in the space so that it faces the door to acquire an image of an interior of the space including the door; door area defining means for setting a predetermined door defining area for the image; door extracting means for extracting a door image from the door defining area of the image; door open/closed state determining means for determining whether the door is open or closed based on an output of the door extracting means; passenger area defining means for setting a predetermined passenger defining area for the image; passenger extracting means for extracting a passenger image from the passenger defining area of the image; passenger presence determining means for determining whether a passenger is present or not based on an output of the passenger extracting means; integrating means for determining whether a passenger is confined or not by integrating judgements of the door open/closed state determining means and the passenger presence determining means; and alarming means for issuing an alarm to outside if a passenger has been confined, based on an output of the integrating means.
In a preferred form, the door extracting means has: door highlighting means for highlighting a position of an edge of a door in the door defining area; data time series storing means for successively storing in time series door edge position data emphasizing the position of the edge of the door; and door operation extracting means for extracting an opening/closing operation of the door from the time series data, and the door open/closed state determining means determines whether the door is open or closed based on an output of the door operation extracting means.
The passenger extracting means has: an image temporary storage memory for temporarily saving a previous image; comparing means for performing comparison between an image in the temporary storage memory and an image acquired by the image acquiring means; and difference pixel number counting means for counting a number of pixels of a difference between the two images based on an output of the comparing means, wherein the passenger presence determining means determines whether there is a passenger or not based on an output of the difference pixel number counting means.
The image monitoring apparatus further includes destination floor recognizing means for recognizing a destination floor, and door operation timing calculating means for calculating a time before the door is opened next based on an output of the destination floor recognizing means, wherein the integrating means determines that a passenger has been confined based on determinations of the door open/closed state determining means and the passenger presence determining means and if the door is not opened when the time is reached.
According to another aspect of the present invention, there is provided an image monitoring apparatus for monitoring an opening/closing door, comprising: image acquiring means provided so that it faces the door to acquire an image including the door; door area defining means for setting a predetermined door defining area for the image; door extracting means for extracting a door image from the door defining area of the image; and door operation evaluating means for detecting whether the door is open or closed based on an output of the door extracting means and outputting a detection signal to an external device.
In a preferred form, the alarming means is provided remotely from the image acquiring means.
According to yet another aspect of the present invention, there is provided an image monitoring method for monitoring an interior of a closed space having an opening/closing door, comprising: an image acquiring step for acquiring an image of an interior of the space including the door by an image capturing device provided in the space so that it faces the door; a door area setting step for setting a predetermined door defining area for the image; a door extracting step for extracting a door image from the door defining area of the image; a door open/closed state determining step for determining whether the door is open or closed based on an output of the door extracting step; a passenger area setting step for setting a predetermined passenger defining area for the image; a passenger extracting step for extracting a passenger image from the passenger defining area of the image; a passenger presence determining step for determining whether a passenger is present or not based on an output of the passenger extracting step; an integrating step for determining whether a passenger is confined or not by integrating determination results of the door open/closed state determining step and the passenger presence determining step; and an alarming step for issuing an alarm to outside if a passenger has been confined, based on an output of the integrating step.
In a preferred form, the door extracting step includes: a door highlighting step for highlighting a position of an edge of a door in the door defining area; a data time series storing step for successively storing in time series door edge position data emphasizing the position of the edge of the door; and a door operation extracting step for extracting an opening/closing operation of the door from the time series data, wherein the door open/closed state determining step determines whether the door is open or closed based on an output of the door operation extracting step.
The passenger extracting step includes: an image temporary storage step for temporarily saving a previous image; a comparing step for performing comparison between an image saved in the temporary storage step and an image acquired by the image acquiring step; and a difference pixel number counting step for counting a number of pixels of a difference between the two images based on an output of the comparing step, wherein the passenger presence determining step determines whether there is a passenger or not based on an output of the difference pixel number counting step.
The image monitoring method further includes a destination floor recognizing step for recognizing a destination floor, and a door operation timing calculating step for calculating a time before the door is opened next based on an output of the destination floor recognizing step, wherein the integrating step determines that a passenger has been confined based on determination results of the door open/closed state determining step and the passenger presence determining step and if the door is not opened when the time is reached.
According to another aspect of the present invention, there is provided an image monitoring method for monitoring an opening/closing door, comprising: an image acquiring step for acquiring an image including the door by an image capturing device provided so that it faces the door; a door area setting step for setting a predetermined door defining area for the image; a door extracting step for extracting a door image from the door defining area of the image; and a door operation evaluating step for detecting whether the door is open or closed based on an output of the door extracting step and outputting a detection signal to an external device.
In a preferred form, the alarming step remotely issues an alarm to the image capturing device.